[aprssig] New-N paradigm and LOCALINFO Freq Objects

Iain Young, G7III g7iii at g7iii.net
Tue Sep 24 16:22:53 CDT 2013


On 24/09/13 21:59, Stephen H. Smith wrote:
> On 9/24/2013 4:11 PM, Robert Bruninga wrote:
>>> ... [maybe]a directed path rather than WIDE2-1.
>>> >For example, you might advertise 146.94-RI
>>> >with a path of VERMLN to specifically target users
>>> >north of the repeater...
>> Seems like a good idea on the surface... BUT... While this may satisfy
>> the
>> need to inform users in the VERMLN area, it violates three principles of
>> the LOCALINFO paradigm.
>>
>> 1) It uses a hop, meaning it will blindly collide with  users in the
>> VERMLN area because the digi (nor VERMLN) that is sourcing this packet
>> into the network CANNOT HEAR ALL THE USERS of VERMLN.  Hence the network
>> suffers reliability.  Hence the rule, only source these at the digi
>> direct.
>
>
> So HOW DO you reconcile this with the fact that, in the vast open
> thinly-populated expanses of the US and Canadian great plains and
> prairies, the voice repeater will probably have 2-3 times the range of
> the co-located digipeater if you don't let surrounding digis also
> announce it.
>
> In densely populated coastal areas (especially where rolling hills force
> a limit on voice coverage well before you are out of the range of the
> co-located digipeater) no hops makes sense.   However, in the
> low-density environment of the plains, where the digi is virtually
> guaranteed to "run out of coverage" long before the voice repeater, 1
> WIDE2-1 hop outward from the co-located digi makes sense.

My own opinion is this:

Bob's rule is a reasonable one in general, designed to prevent un-needed
extra transmissions. This is a good objective.

However, in sparsely populated areas, then you need to adjust
appropriately. If a digi sends out a repeater object with WIDE2-1,
and it goes one hop, so everyone within RF range of the repeater gets
that object then great.

Having another station send a WIDE2-2 that the digi digi's is a
different matter of coourse, although there may be times that's
needed/wanted.

General rules/ideas based on minimising collisions and reducing traffic
are good. Expecting a rule that works well in a built up area to work
out in the plains, or an mountainous region may be asking too much
of the rule.

People need to adapt to the RF environment. If I'm doing a RAYNET (UK
equiv to RACES, ARES etc) duty in a park that can be covered simplex,
that's what we will set up.

If it's in a tougher RF environment, where a cross-band repeater is
needed, then we will do that. Heck, I know of events that need 4 or 5
repeaters, due to the hills and valleys.

It's horses for courses folks :) Oh and don't overload the RF channel,
[whether thats emergency traffic on FM voice or APRS! :)]


73s

Iain


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